Rotating column contact device



Oct. 15, 1963 Filed'may 9, 1960 C. M. DOYLE ROTATING COLUMN CONTACTDEVICE 2 Sheets-Sheet 1 3,107,218 RGTATENG COLUMN CONTACT DEVICE CollinM. Doyle, 1444 Lake Shore Drive, Chicago 10, Ill. Filed May 9, 1960,Ser. No. 27,651 9 Claims. (Cl. 23315) This invention relates generallyto improvements in retating contact devices and methods of the typetypified by the devices disclosed in such patents as 2,281,796,2,286,157, and 2,670,132.

More particularly, the invention relates to a new and improved contactdevice of the character described but which is constructed and functionsin a manner which is radically ditl'erent from that of the said patenteddevices.

The basic application of the subject devices is in operations where itis necessary or desirable to bring into intimate contact two fluids, asfor example two liquids for the purpose of extracting or separating acomponent from one of said liquids. The method, construction andoperation of the device is based upon certain physical laws andproperties of the reactants such as the total or partial immiscibilityand varying densities of any two given reactants, and the devices aremost advantageously utilized in operations such as purification,chemical treatment, and solvent extraction.

Generally, the prior devices comprised a sealed cylindrical rotor inwhich were positioned a plurality of spaced concentric cylindricalbands. The bands were formed with a plurality of perforations oropenings. The heavier liquid or other reactant was admitted into therotor at the center thereof and the lighter liquid was admitted into therotor under pressure at the periphery thereof. When the rotor wasoperated at high speeds, the centrifugal force created thereby cause theheavier liquid to travel through the maze of perforations outwardlytoward the periphery of the rotor. Simultaneously, the pressurizedlighter liquid was forced to travel inwardly toward the center of therotor. During the described movements of the two liquids, the same werebrought into intimate contact so that the function of the process couldbe accomplished, and means were then provided for removing the lighterliquid from the center of the rotor and the heavier liquid from theperiphery of the rotor,

While the prior devices unquestionably represented a great advance oversuch earlier contact devices as the static column, the rotating disccolumn and the mix tank centrifugal separator, exhaustiveexperimentation has proven that the theories which dictated theconstruction of said prior devices are actually erroneous. Thus, it hasbeen determined that while the described prior devices functioned with areasonable modicum of efficiency, the erroneous principles whichgoverned their construction and operation greatly limited theirefficiency.

Referring specifically to said Patent No. 2,670,132, it will be notedthat the essential consideration in that device appears to be thesupposition that the primary contacting efiect between the two liquidsis effected by a jet action of the liquids through the relatively smallopenings formed in the concentric separator bands. Thus, the patenteddevice is based upon the premise that the mixing occurs when the twoliquids pass simultaneously through a single small opening. Any surfacecontact of the liquids in the spaces between the separator bands isdescribed as being an unimportant and even undesirable 3,107,218Patented Oct. 15, 1963 factor. As a matter of fact, the patented deviceis actu-' ally provided with means for reducing or preventing any suchsurface contact. Thus, in keeping with the de scribed basic supposition,the patented device employs relatively small openings (0.007 to 0.080inch) and depends upon relatively high speeds of rotation (4,000 rpm.)to create the said jet action.

Contrary to the basic supposition of the said patent, I have determinedexperimentally and in accordance with the basic laws of physics (as Willsubsequently be more fully described), that substantially all of theintimate contacting of the liquids occurs as a result of their surfacecontact in the areas between the separator bands. This being the case,it has been found that the distinctive structure of the said priordevice which is based upon the erroneous supposition of jet action isactually a handicapping limitation upon the efficiency of that device.

It is therefore an important object of this invention to provide arotating column contact device, the construction and operation of whichis based upon and advantageously utilizes the fact that the primarycontacting effect occurs as a result of the surface contact of theliquids in the areas between the separator bands. Thus, the invent-ionis truly a rotating column which utilizes centrifugal forces as a sourceof mixing energy.

In further keeping with the jet action supposition,-

the said patent claimed that it was important that the spacing betweenthe separators bands decrease as the radii of the bands increase. Thus,this varied spacing was allegedly an inverse function of the radius, sothat the spacin decreased outwardly from the center of the rotor.Although the mathematical description of the spacing is not too clear,any spacing which decreases outwardly tends to defeat the very functionswhich such devices are intended to perform. This is true because thegreatest amount or" centrifugal force and hence mixing energy is presentat the point in the rotor which has the greatest linear velocity. Thispoint is, of course, at the periphery of the rotor. Thus, to obtain thegreatest possible amount of actual mixing and consequently the greatestamount of liquid separation or extraction, the volumes of the liquidsshould be greatest at the periphery. Obviously, then, the spacingbetween the separator bands should be greatest near the periphery of therotor, or at least not less than at any other point.

It is therefore another important object of this inven-' tion to provide:a rotating column contact device of the character described in whichthe spacing between the separator bands increases as the radii of thebands increase, or in the alternative, the spacing is at least uniform.

A further object is to afioi'd a rotating column contact device of thecharacter described in which the openings in the separator bands aresubstantially larger than heretofore, thus taking full advantage of thegravitational forces set up in the rotating column to insure thegreatest amount of surface contact of the liquids between the bands. 7 I

As already indicated, it was heretofore necessary to operate the saidprior devices at a fixed relatively high speed of approximately 4,000r.p.m. in order to achieve the desired ,jet action. It is well knownthat in certain applications, such high speeds are not only unnecessary,

but are actually undesirable. Thus, for example, in the removal ofcalfein from coffee with trichlcrethylenc, these two liquids mustbe-mixed very gently in order to avoid emulsification. Similarly, in theremoval of penicillin from fermented liquor with chloroform, such highspeeds result in an undesirable stable emulsion. To combat theseproblems it was often found necessary to employ certain wetting agents,which in turn created new problems by affecting the surface tensions anddensities of the liquids.

A related problem resulting from the use of a fixed speed of rotation isrelated to the fact that the mixing energy required to thoroughly mixany two liquids is directly proportional to the volumetric ratios of theliquids. Thus, for example, a much greater amount of mixing energy isrequired to mix two liquids which are in the volumetric ratio of l to500 than is required to mix two liquids which are in the ratio of lto 1. Obviously, then, with a fixed speed of rotation, the device isoften operating at a speed far in excess of that actually required.

To compensate for this great loss of elficiency, it was often necessaryto operate the prior devices at maximum throughput at all times;

Still another object therefore, is to provide a rotating column contactdevice of the character described which may be operated at variablespeeds so that the greatest control over the mixing of the liquidsismaintained at all times. A related object is to provide a device of thecharacter described in which the speed of rotation may be varied tocompensate for variations in throughput so that maximum efficiency isalways achieved. I

Still a further object is to afford a rotating column contact device ofthe character described which may be operated at the slowest speedconsistent with maximum efiiciency, thereby prolonging the life of thedevice. A related object is to afford a device of the characterdescribed having greater diameter (i.e., volume capacity) and number ofmixing stages than heretofore possible, and still maintain theoperational stresses well within the stress limits of ordinaryconstruction materials.

Depending upon the physical characteristics of the liquids used, it isknown that varying areas of settling or clarification are required forefficient separation of the two liquids after mixing. Thus, while theoutput position of the two liquids is always constant, it is oftendesirable to vary their input positions to provide a greater or smallerarea of clarification.

Yet another object therefore, is to provide a rotating column contactdevice of the character described in which the input positions of theliquids may be varied as required, thereby varying the area of settlingor clarification.

Yet a further object is to afford a rotating column contact device ofthe character described having removable means for gaining access to therotor for purposes of cleaning, repair and the like.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel featuresof construction, arrangement and a combination of parts hereinafterfully described, illustrated in the accompanying drawings, andparticularly pointed out in the appended claims, it being understoodthat various changes in the form, proportion, size and minordetails ofthe structure may be made without departing from the spirit orsacrificing any of the advantages of theinvention.

For the purpose of facilitating an understanding of my invention, 1'have illustrated in the accompanying drawings a preferred embodimentthereof, froman inspection of which, when considered in connection withthe following description, my invention, its mode of construction,assembly and operation, and many of its advantages should be readilyunderstood and appreciated.

Referring to the drawings in which the same characters of reference areemployed to indicate corresponding or similar parts throughout theseveral figures of the drawmgs:

FIG. 1 is a vertical sectional view of a device embodying the invention,with portions thereof being shown in elevation;

FIG. 2 is an end elevational view of the device;

FIG. 3 is an enlarged fragmentary detail sectional View of the outermostseparator bands illustrating the manner in which the liquids flowtherethrough and are mixed therebetween; and

FIG. 4 is an enlarged fragmentary detail sectional view showing asomewhat exaggerated arrangement of the separator bands wherein thespacing therebetween increases as their radii increase.

Referring now to FIG. 1 of the drawings, the reference numeral 10indicates generally the rotating column contact device. The device it?may comprise a pair of standards 12, 12 through which is journaled arotating shaft 14. Connected to the shaft 14 is a cylindrical rotatingcolumn indicated generally by the reference numeral 16. Asemi-cylindrical housing such as 18 may be mounted on the standards 12for'encasing the rotating column 16. The housing 18 may he hingedlyconnected as at 20 (see H6. 2) and have a handle such as 22 so thatready access may be had to the column 16 for purposes of servicing,maintenance, cleaning and the like.

The shaft 14 may be journaled in 'any suitable maner. Thus, thestandards 12 may include a pair of aligned split rings 24, 24. Seated ineach of the split rings 24 may be the outer race of an annular ballbearing 26. Suitable means such as a threaded lock ring 28 and a keyingmember 34) may be employed for locking the shaft 14 in operationalposition. Annular cap members 32, 32 may be connected to the standards12 for encasing the ends of the shaft 14. Each of the cap members 32 maybe provided with suitable connecting means such as 34, for connecting tothe cap members a pair of conduit sections 36 and 38 whose function willbe subsequently described.

The column 16 comprises a pair of circular plates 49 and 42 which may beintegrally formed with or connected to the shaft 14 in any suitablemanner. Thus, in the embodiment illustrated, the shaft 14 is formed witha pair of annular flanges 44, and the plates 4! and 42 are securedthereto by means of the bolts 46. The plates 40 and 42 are connectedtogether adjacent their periphery by a cylindrical shell 48, said shellbeing secured to said plates by a plurality of bolts such as 50. Aplurality of concentric perforated separator bands 52 are fixedlypositioned between the plates 40. and 42. Each band is formed with aplurality of perforations such as 53 therethrough. trated, that thebands 52 are arranged so that the spac ing between any pair thereofincreases as their radii increase, for reasons which will becomeapparent as the description proceeds.

Formed through the separator bands 52 are a plurality of groups ofaligned holes'such as 54, 56 and 58 Removably positioned through saidgroups of holes 54, 56 and 58 are rods such as 60, 62 and 64respectively. Each of the rods 69, 62 and 64 is threaded at its innerend for connection to the shaft 14 in. a manner which will besubsequently described. The shell 48 is also formed with a plurality ofthreaded openings such as 66, 68 and 7G, each of said threaded openingsbeing aligned respectively with one of said groups of aligned holes 54,56 and 58. A threaded plug such as 72 is removably positioned in each ofsaid openings 66, 68 and 79. It will thus be apparent that when desired,the plugs 72 may be removed for purposes of servicing or cleaning the Itis important to note, as illusis introduced and the heavier liquidwithdrawn from near the periphery of the column. With these objects inmind, the following means may be provided. The shaft 14 is centrallybored at both ends thereof to provide a pair of axial openings 74 and 76which terminate at points near the middle of the shaft, but are spacedapart as shown in FIG. 1 of the drawings. The axial openings 74 and 75are formed with annular shoulders 78 and 80 respectively to affordenlarged diameter opening portions 82 and 84.

Positioned in the opening 74 is a tube 86 which is provided with aplurality of holes 88 formed in the wall of said tube adjacent the innerend thereof. A plurality of bores 90 is drilled radially in the shaft 14with each of said bores being aligned with a respective hole 38. Each ofthe bores 96 is complement-arily threaded to removably receive the innerend of one of the rods 60. It will thus be apparent that each of thebores communicates with the opening 74 and a rod 60. A plurality ofopenings such as 92 is also drilled in the shaft 14 so that the enlargedportion 82 of the axial opening 74 communicates with the center of theinterior of the column 16. The conduit section 36 is provided withsuitable conduits (not shown) which are aligned respectively with thetube 86 and the enlarged diameter opening 82. Attached to said conduitsection 36 and communicating with said conduits is a heavy liquid inletpipe 94 and a light liquid outlet pipe 96.

In a similar manner a tube 98 having a plurality of holes 100 adjacentthe inner end thereof is positioned in the opening 76. A plurality ofbores 102 is drilled in the shaft 14 with each of said bores beingaligned with a respective hole 100. Each of the bores 1112 iscomplementarily threaded to removably receive one of the rods 62. Aplurality of openings such as 104 is also drilled in the shaft .14, andeach of said openings 184 is complementarily threaded to removablyreceive one of the rods 64. The conduit section 3 8 is similar to theconduit section 36 and has connected thereto a light liquid inlet pipe106 and a heavy liquid outlet pipe 108.

, Referring to the rods 60, 62 and 64, it will be seen that the same areof varying construction, one from the other. Thus, each of the rods 64is hollow throughout substantially its entire length, and has an opening110 formed therein beyond the outermost separator band 52, or adjacentthe periphery of the column 16'. As indicated by the flow arrows, theheavy liquid is withdrawn from the column 16 by flowing through theopenings 110 into the rod 64 and out of the heavy liquid outlet pipe 108along the course already described. Since it is contemplated that thepositioning of the openings 119 is always the same, it is apparent thatthe outlet position of the heavy liquid Within the column 16 is alwaysadjacent the periphery of said column. Similarly, as indicated by theflow arrows, the light liquid is withdrawn from the center area of thecolumn by flowing directly through the openings 92 and out of the lightliquid outlet pipe 96 along the course previously described. Since theradial positioning of the openings 92 is constant, it is thus apparentthat the outlet position of the light liquid within the column 16 isalso constant.

It is important to note, however, that the rods 60 and 62 illustratedare hollow for only a portion of their respective lengths. Thus the rod612/ has an opening 112 intermediate its length but nearer to the innerend thereof, while the rod 62 has an opening 114 intermediate its lengthbut near the outer end thereof. It is contemplated that the rods 69 and62 may be interchanged with rods which are similar but have theiropenings i112 and 114 formed in varying positions along the lengthsthereof. Since the openings 112 and 114 comprise the inlet openings intothe column 16 for the heavy liquid and light liquid respectively, itwill thus be apparent that the inlet position of both liquids may bevaried at will.

6 The described adjustability of the input positions of the liquidsrenders my device adaptable for virtually any operation of the typeunder consideration irrespective of the physical characteristics of theliquids involved. It is well known that the area required for any twoliquids to clarify or settle after the same have been mixed varies withthe physical characteristics and volumetric ratios of the liquids used.It thus becomes necessary to vary the clarification area, or area whereno mixing occurs, to suit the characteristics of the particular liquidsbeing used. It should thus be apparent, that by providing for theadjustment of the position of the input openings 1 12 and 114 asdescribed, I have provided a simple means for varying the clarificationarea.

To rotate the shaft 14 and column 16, one side of the shaft (the rightside as viewed in FIG. 1) is provided with a sheave 116 upon which aremounted a plurality of drive belts 118 (see FIG. 2). Each of the drivebelts 118 may be connected to a motor of different operational speed(not shown), so that the speed of rotation of the column 16 may becorrespondingly controlled for purposes which will be more fullydescribed hereinafter. It is contemplated that the operational speedranges will be between 300 r.p.m. [and 1,000 r.p.m. It should beunderstood, of course, that instead of the multiple motors and drivebelts described, a single drive belt and motor with variable speedcontrol gear box may be employed with equally satisfactory results.

The operation of the device may now be described as follows. The inletopenings 112 and 114- are pre-set according to the number of mixingstages and area of clanification required by the particular operation.The heavy liquid and light liquid respectively are introduced into thecolumn 16 through said openings 112 and 114 in the manner described. Theshaft 14 and column 16 are ro tated at the'exact predetermined speedsuitable for the particular operation. When the column 16 is thusrorated, the heavy liquid is forced outwardly by centrifugal forcethrough the perforated bands 52. Simultaneously, the pressurized lightliquid is forced inwardly through the perforated bands 52. As eitherliquid passes through a band 52, the same is broken up into dropletsbecause of the plurality of perforations 53 in the band. A violent andintimate mixing of both droplet-dispersed liquids then takes place inthe areas between each pair of bands 52. After both liquids havepassedthrough all of the mixing stages, the same continue on through thepre-set nonmixin-g or clarification areas. The light liquid is thenwithdrawn from the center of the column 16 and the heavy liquid frorntheperiphery thereof in the manner already described.

The precise manner in which the above described violent mixing of theliquids in the areas between the bands 52 occurs will now be explained.In a typical embodiment of the invention, the diameter of the column 16might be 72 inches, so that the diameter of the outermost band 52 mightbe 64 inches. In such a device, the innermost band 52 would have adiameter of about 24 inches. Assuming a speed of rotation of 1,000r.p.m., we can determine by simple well known calculations that thelinear speed of a point on the outermost band 52 will be approximately17,000 feet per minute. By the same arithmetic calculation, the linearspeed of a point on the innermost band 52 will be approximately only6,300 feet per minute. It is thus apparent that a light liquid which isintroduced at the periphery of the column 16 must decelerate some 11,000feet per minute in its passage through the column. Similarly, a heavyliquid which is introduced at the center of the column must acceleratesome 11,000 feet per minute.

Generally, both liquids travel co-currently or in the same direction asthey pass through the column 16. This direction of travel is of coursethe same as the direction of rotation of the column itself. However, itshould now be apparent that as a liquid passes fromone band to the next,this liquid is either accelerated or deceleratcd as above described.Since the passage of a liquid from one band 52 to the next takes but ashort moment of time, the described acceleration or deceleration thusimparts a violent or jolting action to that liquid. In the case of thedecelerating lighter liquid, the jolting action is in a directionopposed to the general direction of the liquids travel. On the otherhand, the jolting action of the accelerating heavy liquid is in the samedirection as the general direction of the liquids travel. There thusoccurs a violent cross-collision between the two liquids in the areabetween any two bands 52.

Referring now specifically to FIG. 3 of the drawings, the reasons forincreasing the spacing between the bands 52 in direct proportion to theincrease in the length of their radii, rather than decreasing the sameas heretofore, will now become apparent. As indicated, the outermostband 52 has a linear velocity of approximately 17,000 feet per minute.Assuming that the next band 52 is spaced about 2 inches from theoutermost band (i.e., a diameter of about 60 inches), the linearvelocity of a point on that band is approximately 15,000 feet perminute. it should be ap parent that the greatest amount of accelerationor deceleration will occur between the two bands which are spacedfarthest apart. Thus, for example, the acceleration or decelerationbetween the two innermost bands which may be only about200 inch apart(see FIG. 4) is virtually negligible. Actually, in the case of the twoinnermost bands, the change of velocity would be about 100 feet perminute as compared to the described change of about 2,000 feet perminute between the two outermost bands. Obviously then, the most violentcross-collision and mixing willoccur between the bands which are spacedfarthest apart.

, the periphery of the column 16, it will be apparent that the greatestpossible volume of the liquids should desirably he brought into contactnear the periphery of the column.

In this regard, it is obvious that a much larger volume of the liquidswill collide in the 2 inch space between the two outermost bands than inthe .200 inch space between the'two innermost bands.

As previously indicated, my device actually comprises a rotating columnin which centrifugal force is used to impart mixing energy totheliquids. This being the case, I have found it desirable to utilize thegravitational forces set up in the rotating column. In thisregard, theperforations in the bands 52 are considerably larger than heretofore,the same ranging in diameter or size from 7 (.094) inch to /2 (.500)inch. It has also been deter- 'mined that for most efiicient utilizationof the gravitational forces, the area of the perforations iu' the bandsshould be approximately to 11 times the area of the admission openingsof the liquids. Thus, the innermost band may have a perforation area ofabout 5 times the area of theliquid admission openings, while theperforations of the outermost band may be about ll times the area of theliquid admission openings.

From the foregoing description and drawings, it should be apparent thatI have provided a novel rotating column contact device. The device isdesigned to most efiiciently utilize the known applicable physical laws.Thus, for example, the space between the separator bands increases astheir radii increase. The input positions of the two liquids may bereadily varied to provide any desired area of clarification. The deviceemploys variable speed drive means so that complete control over themixing of the liquid may be maintained at all times. The variable speedalso permits compensation for less than maximum throughput,

so that maximum efliciency is always maintained. Since the device neednever be operated at a speed in excess of that required, the stresses onthe materials of construction are greatly reduced. Thus columns ofgreater diameter and volume than heretofore practicable may be safelyand efliciently employed. Similarly, a longer life for the rotatingmembers themselves is thereby assured.

it is believed that my invention, its mode of construction and assembly,and many of its advantages should be readily understood from theforegoing without further description, and it should also be manifestthat while a preferred embodiment of the invention has been shown anddescribed for illustrative purposes, the structural details arenevertheless capable of wide variation within the purview of myinvention as defined in the appended claims.

What I claim and desire to secure by Letters Patent of the United Statesis:

l. A rotating column contact device for effecting intimate contactbetween relatively immiscible liquids of different densities comprising;a rotor, means for supplying heavier liquid to and means for removinglighter liquid from the interior of said rotor adjacent the axisthereof, means for forcing lighter liquid into and means for dischargingheavier liquid from the interior of said rotor adjacent the peripherythereof, a plurality of spaced concentric separator bands positioned insaid rotor, each of said bands being formed with a plurality of openingstherethrough, the spacing between adjacent bands increasing as their-radii increase.

2. The device of claim 1 in which the size of said openings are from.094 to .500 inch in diameter.

3. The device of claim 1 in which said first means includes a heavierliquid inlet hole and said third means includes a lighter liquid inlethole, and the total area of the openings in each of said bands is from 5to 11 times the total area of said inlet holes.

4. The device of claim 3 in which the total area of the openings in theinnermostof said bands is 5 times the total area of said inlet holes andthe totalarea of the openings in the outermost of said bands is 11 timesthe total area of said inlet holes.

5. The device of claim 1 in which said first means and third meansinclude a heavier liquid inlet hole and lighter liquid inlet holerespectively, and means for readily changing the position of said inletholes relative to the axis and periphery of said rotor. V

6. The device of claim .5 in which said last-mentioned means includesportions of said separator bands having a plurality of groups of alignedholes formed therein and portions of the periphereal shell of said rotorhaving a plurality of service openings formed therein one in align mentwith each of said groups of aligned holes, a service plug removablyclosing each of said service openings, and a plurality of rods each ofwhich is removably positionable in one of said groups of aligned holes,said inlet holes being formed in said rods at varying positions relativetheir length.

.moving said liquids from theinterior of said rotor; said heavier liquidbeing introduced and said lighter liquid being removed in the proximity.of'the rotor axis and said lighter liquid being introduced and saidheavier liquid being removed in the proximity of the periphery of therotor; a plurality of spaced'concentric bands positioned in said rotor,each of said bands being formed with a plurality of openingstherethrough, the spacing between adjacent bands increasing as theirradii increase.

8. The device of claim 7 in which said openings have a dimension of from.094- to .500 inch.

9. A rotating column con-tact device for effecting intimate contactbetween immiscible or partially immiscible liquids of differentdensities comprising, a cylindrical roj tor including a central shaft,means including a heavier liquid inlet hole for supplying heavier liquidinto said rotor adjacent the axis thereof, means including a lighterliquid inlet hole for forcing lighter liquid into said rotor adjacentthe periphery thereof, means for readily adjusting the positions of saidinlet holes relative to said axis and periphery respectively, means forremoving said lighter liquid from said rotor adjacent the axis thereof,means for discharging said heavier liquid from said rotor adjacent theperiphery thereof, a plurality of spaced concentric separator bandspositioned in said rotor, the spacing between adjacent bands increasingas their radii increase, each of said bands being formed with aplurality of openings through which, on rotation of the rotor, theliquids pass and are dispersed into droplets, said openings having adimension of from .094 to .500 inch, and "ariable speed drive meansconnected to said shaft for ro- 18 tating said rotor, said drive meansadapted to operate at speeds of from 380 to 1,000 revolutions perminute.

References Cited in the fiie of this patent UNITED STATES PATENTS2,093,645 Podbielniak Sept. 21, 1937 2,281,796 Podbielniak May 5, 19422,286,157 Podbielniak June 9, 1942 2,652,975 Angelo Sept. 22, 19532,670,132 Podbielniak Feb. 23, 1954 2,758,783 Podbielniak Aug. 14, 19562,758,784 Podbielniak et a1 Aug. 14, 1956 2,878,993 Podbielniak Mar. 24,1959 2,880,929 Podbielniak Apr. 7, 1959 3,050,238 Doyle et al Aug. 21,1962

1. A ROTATING COLUMN CONTACT DEVICE FOR EFFECTING INTIMATE CONTACTBETWEEN RELATIVELY IMMISCIBLE LIQUIDS OF DIFFERENT DENSITIES COMPRISING;A ROTOR, MEANS FOR SUPPLYING HEAVIER LIQUID TO AND MEANS FOR REMOVINGLIGHTER LIQUID FROM THE INTERIOR OF SAID ROTOR ADJACENT THE AXISTHEREOF, MEANS FOR FORCING LIGHTER LIQUID INTO AND MEANS FOR DISCHARGINGHEAVIER LIQUID FROM THE INTERIOR OF SAID ROTOR ADJACENT THE PERIPHERYTHEREOF, A PLURALITY OF SPACED CONCENTRIC SEPARATOR BANDS POSITIONED INSAID ROTOR, EACH OF SAID BANDS BEING FORMED WITH A PLURALITY OF OPENINGSTHERETHROUGH, THE SPACING BETWEEN ADJACENT BANDS INCREASING AS THEIRRADII INCREASE.